N-bromobutanimide → 5-Bromo-3-(5-tert-butyl-1,3,4-oxadiazol-2-yl)pyrazin-2-amine

HRID 1749668Notes

Reaction equation

HRID 1749668 reaction equation
[Br:1]N1C(=O)CCC1=O.[C:9]([C:13]1[O:17][C:16]([C:18]2[C:19]([NH2:24])=[N:20][CH:21]=[CH:22][N:23]=2)=[N:15][N:14]=1)([CH3:12])([CH3:11])[CH3:10]>C1COCC1>[Br:1][C:22]1[N:23]=[C:18]([C:16]2[O:17][C:13]([C:9]([CH3:12])([CH3:10])[CH3:11])=[N:14][N:15]=2)[C:19]([NH2:24])=[N:20][CH:21]=1

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 867276543-(5-Tert-butyl-1,3,4-oxadiazol-2-yl)pyrazin-2-amine

Product 1

HCID 867276555-Bromo-3-(5-tert-butyl-1,3,4-oxadiazol-2-yl)pyrazin-2-amineYield 90.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

1-Bromopyrrolidine-2,5-dione (18.57 g, 104.36 mmol) was added portionwise to a solution of 3-(5-tert-butyl-1,3,4-oxadiazol-2-yl)pyrazin-2-amine (20.8 g, 94.87 mmol) in THF (320 mL) and the solution was stirred at room temperature for 16 hours. The reaction mixture was concentrated and the residue was dissolved in dichloromethane (300 mL), washed with water (2×150 mL), brine, dried over magnesium sulfate and concentrated. The solvent was evaporated and the crude product was purified by flash chromatography on silica gel, eluting with 0 to 10% ethyl acetate in dichloromethane. The solvent was evaporated to dryness to afford 5-bromo-3-(5-tert-butyl-1,3,4-oxadiazol-2-yl)pyrazin-2-amine (25.5 g, 90%) as a beige solid: 1H NMR Spectrum; (CDCl3) 1.52 (9H, s), 8.23 (1H, s); Mass Spectrum [M+H]+=300.

Workup

  1. concentrationThe reaction mixture was concentrated
  2. dissolutionthe residue was dissolved in dichloromethane (300 mL)
  3. washwashed with water (2×150 mL), brine
  4. dry with materialdried over magnesium sulfate
  5. concentrationconcentrated
  6. customThe solvent was evaporated
  7. customthe crude product was purified by flash chromatography on silica gel
  8. washeluting with 0 to 10% ethyl acetate in dichloromethane
  9. customThe solvent was evaporated to dryness

Sources & evidence

ORD record
ord-a2a00dff89354347b1e5b420963b914a
Source dataset
uspto-grants-2015_10
Patent number
US09156831B2

Reaction notes

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